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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1Ioctl Numbers
219 October 1999
3Michael Elizabeth Chastain
4<mec@shout.net>
5
6If you are adding new ioctl's to the kernel, you should use the _IO
7macros defined in <linux/ioctl.h>:
8
9 _IO an ioctl with no parameters
10 _IOW an ioctl with write parameters (copy_from_user)
11 _IOR an ioctl with read parameters (copy_to_user)
12 _IOWR an ioctl with both write and read parameters.
13
14'Write' and 'read' are from the user's point of view, just like the
15system calls 'write' and 'read'. For example, a SET_FOO ioctl would
16be _IOW, although the kernel would actually read data from user space;
17a GET_FOO ioctl would be _IOR, although the kernel would actually write
18data to user space.
19
20The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter
21or number from the table below. Because of the large number of drivers,
22many drivers share a partial letter with other drivers.
23
24If you are writing a driver for a new device and need a letter, pick an
25unused block with enough room for expansion: 32 to 256 ioctl commands.
26You can register the block by patching this file and submitting the
27patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and
28I'll register one for you.
29
30The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number
31to distinguish ioctls from each other. The third argument to _IOW,
32_IOR, or _IOWR is the type of the data going into the kernel or coming
33out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use
34sizeof(arg) as the third argument as this results in your ioctl thinking
35it passes an argument of type size_t.
36
37Some devices use their major number as the identifier; this is OK, as
38long as it is unique. Some devices are irregular and don't follow any
39convention at all.
40
41Following this convention is good because:
42
43(1) Keeping the ioctl's globally unique helps error checking:
44 if a program calls an ioctl on the wrong device, it will get an
45 error rather than some unexpected behaviour.
46
47(2) The 'strace' build procedure automatically finds ioctl numbers
48 defined with _IO, _IOW, _IOR, or _IOWR.
49
50(3) 'strace' can decode numbers back into useful names when the
51 numbers are unique.
52
53(4) People looking for ioctls can grep for them more easily when
54 this convention is used to define the ioctl numbers.
55
56(5) When following the convention, the driver code can use generic
57 code to copy the parameters between user and kernel space.
58
59This table lists ioctls visible from user land for Linux/x86. It contains
60most drivers up to 2.6.31, but I know I am missing some. There has been
61no attempt to list non-X86 architectures or ioctls from drivers/staging/.
62
63Code Seq#(hex) Include File Comments
64========================================================
650x00 00-1F linux/fs.h conflict!
660x00 00-1F scsi/scsi_ioctl.h conflict!
670x00 00-1F linux/fb.h conflict!
680x00 00-1F linux/wavefront.h conflict!
690x02 all linux/fd.h
700x03 all linux/hdreg.h
710x04 D2-DC linux/umsdos_fs.h Dead since 2.6.11, but don't reuse these.
720x06 all linux/lp.h
730x09 all linux/raid/md_u.h
740x10 00-0F drivers/char/s390/vmcp.h
750x12 all linux/fs.h
76 linux/blkpg.h
770x1b all InfiniBand Subsystem <http://infiniband.sourceforge.net/>
780x20 all drivers/cdrom/cm206.h
790x22 all scsi/sg.h
80'#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem
81'$' 00-0F linux/perf_counter.h, linux/perf_event.h
82'&' 00-07 drivers/firewire/nosy-user.h
83'1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl
84 <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/>
85'2' 01-04 linux/i2o.h
86'3' 00-0F drivers/s390/char/raw3270.h conflict!
87'3' 00-1F linux/suspend_ioctls.h conflict!
88 and kernel/power/user.c
89'8' all SNP8023 advanced NIC card
90 <mailto:mcr@solidum.com>
91'@' 00-0F linux/radeonfb.h conflict!
92'@' 00-0F drivers/video/aty/aty128fb.c conflict!
93'A' 00-1F linux/apm_bios.h conflict!
94'A' 00-0F linux/agpgart.h conflict!
95 and drivers/char/agp/compat_ioctl.h
96'A' 00-7F sound/asound.h conflict!
97'B' 00-1F linux/cciss_ioctl.h conflict!
98'B' 00-0F include/linux/pmu.h conflict!
99'B' C0-FF advanced bbus
100 <mailto:maassen@uni-freiburg.de>
101'C' all linux/soundcard.h conflict!
102'C' 01-2F linux/capi.h conflict!
103'C' F0-FF drivers/net/wan/cosa.h conflict!
104'D' all arch/s390/include/asm/dasd.h
105'D' 40-5F drivers/scsi/dpt/dtpi_ioctl.h
106'D' 05 drivers/scsi/pmcraid.h
107'E' all linux/input.h conflict!
108'E' 00-0F xen/evtchn.h conflict!
109'F' all linux/fb.h conflict!
110'F' 01-02 drivers/scsi/pmcraid.h conflict!
111'F' 20 drivers/video/fsl-diu-fb.h conflict!
112'F' 20 drivers/video/intelfb/intelfb.h conflict!
113'F' 20 linux/ivtvfb.h conflict!
114'F' 20 linux/matroxfb.h conflict!
115'F' 20 drivers/video/aty/atyfb_base.c conflict!
116'F' 00-0F video/da8xx-fb.h conflict!
117'F' 80-8F linux/arcfb.h conflict!
118'F' DD video/sstfb.h conflict!
119'G' 00-3F drivers/misc/sgi-gru/grulib.h conflict!
120'G' 00-0F linux/gigaset_dev.h conflict!
121'H' 00-7F linux/hiddev.h conflict!
122'H' 00-0F linux/hidraw.h conflict!
123'H' 00-0F sound/asound.h conflict!
124'H' 20-40 sound/asound_fm.h conflict!
125'H' 80-8F sound/sfnt_info.h conflict!
126'H' 10-8F sound/emu10k1.h conflict!
127'H' 10-1F sound/sb16_csp.h conflict!
128'H' 10-1F sound/hda_hwdep.h conflict!
129'H' 40-4F sound/hdspm.h conflict!
130'H' 40-4F sound/hdsp.h conflict!
131'H' 90 sound/usb/usx2y/usb_stream.h
132'H' C0-F0 net/bluetooth/hci.h conflict!
133'H' C0-DF net/bluetooth/hidp/hidp.h conflict!
134'H' C0-DF net/bluetooth/cmtp/cmtp.h conflict!
135'H' C0-DF net/bluetooth/bnep/bnep.h conflict!
136'H' F1 linux/hid-roccat.h <mailto:erazor_de@users.sourceforge.net>
137'I' all linux/isdn.h conflict!
138'I' 00-0F drivers/isdn/divert/isdn_divert.h conflict!
139'I' 40-4F linux/mISDNif.h conflict!
140'J' 00-1F drivers/scsi/gdth_ioctl.h
141'K' all linux/kd.h
142'L' 00-1F linux/loop.h conflict!
143'L' 10-1F drivers/scsi/mpt2sas/mpt2sas_ctl.h conflict!
144'L' E0-FF linux/ppdd.h encrypted disk device driver
145 <http://linux01.gwdg.de/~alatham/ppdd.html>
146'M' all linux/soundcard.h conflict!
147'M' 01-16 mtd/mtd-abi.h conflict!
148 and drivers/mtd/mtdchar.c
149'M' 01-03 drivers/scsi/megaraid/megaraid_sas.h
150'M' 00-0F drivers/video/fsl-diu-fb.h conflict!
151'N' 00-1F drivers/usb/scanner.h
152'N' 40-7F drivers/block/nvme.c
153'O' 00-06 mtd/ubi-user.h UBI
154'P' all linux/soundcard.h conflict!
155'P' 60-6F sound/sscape_ioctl.h conflict!
156'P' 00-0F drivers/usb/class/usblp.c conflict!
157'Q' all linux/soundcard.h
158'R' 00-1F linux/random.h conflict!
159'R' 01 linux/rfkill.h conflict!
160'R' C0-DF net/bluetooth/rfcomm.h
161'S' all linux/cdrom.h conflict!
162'S' 80-81 scsi/scsi_ioctl.h conflict!
163'S' 82-FF scsi/scsi.h conflict!
164'S' 00-7F sound/asequencer.h conflict!
165'T' all linux/soundcard.h conflict!
166'T' 00-AF sound/asound.h conflict!
167'T' all arch/x86/include/asm/ioctls.h conflict!
168'T' C0-DF linux/if_tun.h conflict!
169'U' all sound/asound.h conflict!
170'U' 00-CF linux/uinput.h conflict!
171'U' 00-EF linux/usbdevice_fs.h
172'U' C0-CF drivers/bluetooth/hci_uart.h
173'V' all linux/vt.h conflict!
174'V' all linux/videodev2.h conflict!
175'V' C0 linux/ivtvfb.h conflict!
176'V' C0 linux/ivtv.h conflict!
177'V' C0 media/davinci/vpfe_capture.h conflict!
178'V' C0 media/si4713.h conflict!
179'V' C0-CF drivers/media/video/mxb.h conflict!
180'W' 00-1F linux/watchdog.h conflict!
181'W' 00-1F linux/wanrouter.h conflict!
182'W' 00-3F sound/asound.h conflict!
183'X' all fs/xfs/xfs_fs.h conflict!
184 and fs/xfs/linux-2.6/xfs_ioctl32.h
185 and include/linux/falloc.h
186 and linux/fs.h
187'X' all fs/ocfs2/ocfs_fs.h conflict!
188'X' 01 linux/pktcdvd.h conflict!
189'Y' all linux/cyclades.h
190'Z' 14-15 drivers/message/fusion/mptctl.h
191'[' 00-07 linux/usb/tmc.h USB Test and Measurement Devices
192 <mailto:gregkh@linuxfoundation.org>
193'a' all linux/atm*.h, linux/sonet.h ATM on linux
194 <http://lrcwww.epfl.ch/>
195'b' 00-FF conflict! bit3 vme host bridge
196 <mailto:natalia@nikhefk.nikhef.nl>
197'c' all linux/cm4000_cs.h conflict!
198'c' 00-7F linux/comstats.h conflict!
199'c' 00-7F linux/coda.h conflict!
200'c' 00-1F linux/chio.h conflict!
201'c' 80-9F arch/s390/include/asm/chsc.h conflict!
202'c' A0-AF arch/x86/include/asm/msr.h conflict!
203'd' 00-FF linux/char/drm/drm/h conflict!
204'd' 02-40 pcmcia/ds.h conflict!
205'd' 10-3F drivers/media/video/dabusb.h conflict!
206'd' C0-CF drivers/media/video/saa7191.h conflict!
207'd' F0-FF linux/digi1.h
208'e' all linux/digi1.h conflict!
209'e' 00-1F drivers/net/irda/irtty-sir.h conflict!
210'f' 00-1F linux/ext2_fs.h conflict!
211'f' 00-1F linux/ext3_fs.h conflict!
212'f' 00-0F fs/jfs/jfs_dinode.h conflict!
213'f' 00-0F fs/ext4/ext4.h conflict!
214'f' 00-0F linux/fs.h conflict!
215'f' 00-0F fs/ocfs2/ocfs2_fs.h conflict!
216'g' 00-0F linux/usb/gadgetfs.h
217'g' 20-2F linux/usb/g_printer.h
218'h' 00-7F conflict! Charon filesystem
219 <mailto:zapman@interlan.net>
220'h' 00-1F linux/hpet.h conflict!
221'h' 80-8F fs/hfsplus/ioctl.c
222'i' 00-3F linux/i2o-dev.h conflict!
223'i' 0B-1F linux/ipmi.h conflict!
224'i' 80-8F linux/i8k.h
225'j' 00-3F linux/joystick.h
226'k' 00-0F linux/spi/spidev.h conflict!
227'k' 00-05 video/kyro.h conflict!
228'k' 10-17 linux/hsi/hsi_char.h HSI character device
229'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system
230 <http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
231'l' 40-7F linux/udf_fs_i.h in development:
232 <http://sourceforge.net/projects/linux-udf/>
233'm' 00-09 linux/mmtimer.h conflict!
234'm' all linux/mtio.h conflict!
235'm' all linux/soundcard.h conflict!
236'm' all linux/synclink.h conflict!
237'm' 00-19 drivers/message/fusion/mptctl.h conflict!
238'm' 00 drivers/scsi/megaraid/megaraid_ioctl.h conflict!
239'm' 00-1F net/irda/irmod.h conflict!
240'n' 00-7F linux/ncp_fs.h and fs/ncpfs/ioctl.c
241'n' 80-8F linux/nilfs2_fs.h NILFS2
242'n' E0-FF linux/matroxfb.h matroxfb
243'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2
244'o' 00-03 mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps)
245'o' 40-41 mtd/ubi-user.h UBI
246'o' 01-A1 linux/dvb/*.h DVB
247'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this)
248'p' 00-1F linux/rtc.h conflict!
249'p' 00-3F linux/mc146818rtc.h conflict!
250'p' 40-7F linux/nvram.h
251'p' 80-9F linux/ppdev.h user-space parport
252 <mailto:tim@cyberelk.net>
253'p' A1-A5 linux/pps.h LinuxPPS
254 <mailto:giometti@linux.it>
255'q' 00-1F linux/serio.h
256'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
257 linux/ixjuser.h <http://web.archive.org/web/*/http://www.quicknet.net>
258'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c
259's' all linux/cdk.h
260't' 00-7F linux/ppp-ioctl.h
261't' 80-8F linux/isdn_ppp.h
262't' 90 linux/toshiba.h
263'u' 00-1F linux/smb_fs.h gone
264'u' 20-3F linux/uvcvideo.h USB video class host driver
265'v' 00-1F linux/ext2_fs.h conflict!
266'v' 00-1F linux/fs.h conflict!
267'v' 00-0F linux/sonypi.h conflict!
268'v' C0-DF media/pwc-ioctl.h conflict!
269'v' C0-FF linux/meye.h conflict!
270'v' D0-DF drivers/media/video/cpia2/cpia2dev.h conflict!
271'w' all CERN SCI driver
272'y' 00-1F packet based user level communications
273 <mailto:zapman@interlan.net>
274'z' 00-3F CAN bus card conflict!
275 <mailto:hdstich@connectu.ulm.circular.de>
276'z' 40-7F CAN bus card conflict!
277 <mailto:oe@port.de>
278'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
279'|' 00-7F linux/media.h
2800x80 00-1F linux/fb.h
2810x89 00-06 arch/x86/include/asm/sockios.h
2820x89 0B-DF linux/sockios.h
2830x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
2840x89 E0-EF linux/dn.h PROTOPRIVATE range
2850x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range
2860x8B all linux/wireless.h
2870x8C 00-3F WiNRADiO driver
288 <http://www.winradio.com.au/>
2890x90 00 drivers/cdrom/sbpcd.h
2900x92 00-0F drivers/usb/mon/mon_bin.c
2910x93 60-7F linux/auto_fs.h
2920x94 all fs/btrfs/ioctl.h
2930x97 00-7F fs/ceph/ioctl.h Ceph file system
2940x99 00-0F 537-Addinboard driver
295 <mailto:buk@buks.ipn.de>
2960xA0 all linux/sdp/sdp.h Industrial Device Project
297 <mailto:kenji@bitgate.com>
2980xA2 00-0F arch/tile/include/asm/hardwall.h
2990xA3 80-8F Port ACL in development:
300 <mailto:tlewis@mindspring.com>
3010xA3 90-9F linux/dtlk.h
3020xAB 00-1F linux/nbd.h
3030xAC 00-1F linux/raw.h
3040xAD 00 Netfilter device in development:
305 <mailto:rusty@rustcorp.com.au>
3060xAE all linux/kvm.h Kernel-based Virtual Machine
307 <mailto:kvm@vger.kernel.org>
3080xAF 00-1F linux/fsl_hypervisor.h Freescale hypervisor
3090xB0 all RATIO devices in development:
310 <mailto:vgo@ratio.de>
3110xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca>
3120xB3 00 linux/mmc/ioctl.h
3130xC0 00-0F linux/usb/iowarrior.h
3140xCB 00-1F CBM serial IEC bus in development:
315 <mailto:michael.klein@puffin.lb.shuttle.de>
3160xCD 01 linux/reiserfs_fs.h
3170xCF 02 fs/cifs/ioctl.c
3180xDB 00-0F drivers/char/mwave/mwavepub.h
3190xDD 00-3F ZFCP device driver see drivers/s390/scsi/
320 <mailto:aherrman@de.ibm.com>
3210xF3 00-3F drivers/usb/misc/sisusbvga/sisusb.h sisfb (in development)
322 <mailto:thomas@winischhofer.net>
3230xF4 00-1F video/mbxfb.h mbxfb
324 <mailto:raph@8d.com>
3250xF6 all LTTng Linux Trace Toolkit Next Generation
326 <mailto:mathieu.desnoyers@efficios.com>
3270xFD all linux/dm-ioctl.h